IN-VITRO EVOLUTION OF TERMINAL PROTEIN-CONTAINING GENOMES

A new self-sustained terminal protein-primed DNA amplification system has been used to describe In vitro evolutionary changes affecting main tenance of the genome size of bacteriophage phi 29. These changes invo lve generation and efficient amplification of short palindromic molecu les containing an inverted duplication of one of the original DNA ends , A template-switching mechanism is proposed to account for the appear ance of these molecules, After their formation, they would replicate b y means of hairpin intermediates, Relevant kinetic Information about t his DNA replication system has been obtained from the competition betw een the input full-length phi 29 DNA and its derived truncated version s, The physiological relevance of these molecules and the mechanisms t o control their formation are discussed.